Recent mobile phones and other communication terminals can perform data communication by WEB (World Wide Web) connection and so on, in addition to voice communication, transmission/reception of e-mails.
At the time of such data communication, in order to handle high-speed data communication, a multi-link protocol handling a plurality of data links as one logical link routine is being widely utilized.
To enable continuous communication with a network through a base station arranged in a new cell, even when the communication terminal leaves the cell of a base station being communicated with, a mobile phone or other mobile communication terminal performs handover processing in which it searches for the new base station for connection and switches connection to the base station corresponding to its own position during communication.
For example, according to the mobile wireless communication system and wireless communication use mobile terminal disclosed in Patent Document 1, data is transmitted to a base station through a master communication apparatus and a slave communication apparatus. When the slave communication apparatus performs handover processing, the master communication apparatus hands over the communication to a base station for which a call connection is not made.
Patent Document 1: Japanese Patent Publication (A) No. 2002-112308